HTTP headers control caching, security, authentication, content negotiation, and CORS — but they're invisible in normal browsing. Misconfigured headers cause performance degradation (no caching), security vulnerabilities (missing CSP), and broken integrations (wrong CORS). Header analysis should be part of every deployment checklist.
What Is HTTP Header Analyzer?
HTTP headers are key-value pairs sent with every request and response. They control how browsers and servers communicate. Our HTTP Header Analyzer parses headers, identifies security issues, and checks best practices.
How to Use HTTP Header Analyzer on DevToolHub
- Open the HTTP Header Analyzer tool on DevToolHub — no signup required.
- Paste or enter your input data in the left panel.
- See the result instantly in the output panel.
- Copy the result or download it as a file.
Essential Security Headers
The security headers every site should have:
// Recommended response headers
Strict-Transport-Security: max-age=31536000; includeSubDomains
Content-Security-Policy: default-src 'self'; script-src 'self'
X-Content-Type-Options: nosniff
X-Frame-Options: DENY
Referrer-Policy: strict-origin-when-cross-origin
Permissions-Policy: camera=(), microphone=()
// Common caching headers
Cache-Control: public, max-age=31536000, immutable (static assets)
Cache-Control: no-cache, no-store, must-revalidate (API responses)Pro Tips
- Check for HSTS header (Strict-Transport-Security) — it prevents SSL stripping attacks
- Use Cache-Control: immutable for hashed static assets (bundle.a1b2c3.js) for maximum caching
- X-Content-Type-Options: nosniff prevents browsers from MIME-type sniffing
- Set Permissions-Policy to disable browser features your site doesn't use (camera, microphone)
When You Need This
- Auditing website security headers after deployment
- Debugging caching issues and stale content problems
- Analyzing CORS configuration for cross-origin API calls
- Verifying proper content-type and encoding headers
Free Tools Mentioned in This Article